Process for the preparation of polyvinylamine salts



Patented Oct. 11, 1949 .BROCESS FOR'THE PREPARATION OF 'POLYVINYL'AMINE SALTS -Delbert D. Reynolds and William 0. Kenyon, Rochester, N. Y., 'assignors .to EastmanKodak :Gompany, Rochester, N. Y., .a corporation of New Jersey No Drawing. Application-October 30, 1945, Serial No. 6255690 7 Claims. ,1 The invention relates to new synthetic resins and more particularly to :salts and N-acyl derivatives of polyvinylamine.

It is known thats-imple primary amines-can :be

vinylphthalimi-des.

mineral acids and stron inorganic bases.

free carboxyl groups.

. 2 vinylsuccinimide gave a dark-brown solid which hadv a total nitrogen content by the Kjeldahl method of 16.'95,per cent, and an amino nitrogen content of 12.65 per cent by the Van Slyke obtained by the Gabriel synthesis, wherein an 5 method. The hydr9lyzed pr t consisted, N-substituted phthalimide :is hydrolyzed with a therefore, of approxima ly p r cent free strong mineral :acidm an inorganic base at high amino roup and 25 .pe ce t o incompletely temperatures and under pressure to form prihydrolyzed imide groups. The hydIOIySlS of polymary amines and phthalic acid. Under these coni y sl de wlth eth no am e av a yditions, the reaction .is "not clean cut, and pro- 10 i ly product mg but 40 p r cent. of the duces considerable by-products admixed with the nitrogen in the form of prlm' ry a i ro psdesired amine. Usuallythe-amineproductcanbe We e d, howe that s sta t ly separated and purified byimethodsof distillation, p epolyvmylamine salts and Nacyl d riva ives crystallization, extraction, and-thelike. Inpolythereof can be pr p re fr p lyv nyl cyclic mer chemistry, however, the isolation (of .the de- Home o nt m fro 5 o 6 a s n he r sired product by such methods is :not possible. d hill/111g h g aliformulaz In order to obtain a pure resin ion a structural -o H, 0H basis, the reaction must g0 to completion along t the desired path. Otherwise residual orpartially reacted groups will stillbe a 'part of the polymer 3 molecule and cannot be removed therefrom. 'Ob- R t the usual cundltions 0f the p wherein R represents a divalent organic radical, thesis cannot :be employedior -;prepar1ng pure forexample ethylene group, lzmmpylene group, polymer In amines from 1th; 'mrresponding poly 1,2'-phenyle'ne gi'oup'or s'aid groups substituted in the free ositions b on ormor alk l, alkox Polymeric products containing a substantial phenyl, cgrbethoxmyor fi l gen g roups by firs t portion of groups as free amfinoigroups have'also reacting the polyvinyl cyclic imide with hydrabeen prepared from W m d for zine :hydrate to form'asubstituted 'cyclic hydraq P1YY1nY1PhPhahm1de Polyzideof a phthalic acid and then treating this vinylsuccm-imide, bysubjectmg said type of com- :5 compound ith n acid, -for example, hydropounds to hydrolysis presence of Strong chloric, hydrobromic, glacial acetic, alpha-chloj ropropionic or bromobenzoic acid, toobtain corproducts of thls type "9 hydrolysi an responding salts of polyvinylamine admixed with t f had a w themtmgen a phthalyl hydrazide,from which mixture Wehave bined 1D. the iorm of amino nitrogen. In-one 'exbeenxable to isolate practically pure polyvinyl m 'pqlyvmylsucolelmide had F hydtolyzeid amine-salts, that is, a polyvinylamine salt wherewith sodium hydroxide to po f in atleast 90 per cent by weight of the total niacid, with hydrochloric ac d, under mild conditmgen present is intthe form of amino nitrogen tions to a gelatinous material, with concentrated andthe remainder of the nitrogen in the form of hydrochlorifc acid at high temperatures to a 4U incompletely hydrolyzed imide groups. The free pound havmg P per cent of mtmgen base, polyvinylamine, can be freed from our new pr.esent as m gi with t saltsby-generallysimilar procedures to those emmine to materials contaimng both free amino and ployed f obtaining ,orgamcvamines from their In other words: a pure saltcompounds, but preferably under conditions polymeric vlnylaminehad not been obtained, but 5 f from carbon dioxide contamination a polymer containing up to 7.5 percent of the nitrogen presentin the form of -NH2 groups and the balance of the nitrogen in the form of incompletely hydrolyzed imide groups. i

In another example, the hydrolysis of polyvinylphthalimide with hydrobromic acid in phenol gave a product soluble in either acids or bases indicating thereby the presence of a substantial number ofiree amino-and :carboxYl-groups. Concentrated hydrochloric acid hydrolysis of poly- Wehaveiound further that the salts of polyvinylamine can also be prepared from the polyvinyl cyclic imides defined above by following a modified procedure, :wherein a polyvinyl acylamide is first prepared as the intermediate, and then hydrolyzed toasalt of p'olyvinylamine. This particular method of our invention can be performed by the steps of treating the isolated and dried reaction product of a polyvinyl cyclic imide and hydrazine hydrate with an r-acylating agent,

isolating the polyvinyl acylamide so obtained, and hydrolyzing the amide to a salt of polyvinylamine.

The polyvinyl cyclic amides employed as the starting material of our invention can be Drepared by pyrolysis of the N-(beta-acyloxyethyl) derivatives of cyclic imides containing 5 to 6 atoms in the ring and having the general formula:

wherein R represents a divalent organic radical, for example, ethylene group, 1,2-propylene group, 1,2-phenylene group or one of said groups substituted in the free positions by one or more radicals, for example, halogen, alkyl, alkoxy, phenyl, carbethoxy, and polymerizing the N-vinyl cyclic imide obtained. There can be prepared by this method, for example, polyvinylphthalimide from N (beta-acetoxyethyl) phthalimide, polyvinylsuccinimide from N-(beta-acetoxyethyl) succinimide, polyvinyl glutarimide from N-(beta-acetoxyethyl) glutarimide.

Our new salts of polyvinylamine are excellent dispersing agents, as well as intermediates for the preparation of polyvinylamine and other polyvinylamine derivatives. The polyvinyl acylamides of our invention can be employed as intermediates, and as material for film base and synthetic fibers.

It is, accordingly, an object of our invention to provide salts of polyvinylamine. A further object is to provide N-acyl derivatives of polyvinylamine. Another object is to provide a process for preparing salts of polyvinylamine and N-acyl derivatives of polyvinylamine. Other objects of our invention will become apparent hereinafter.

The following examples will serve to illustrate our new compounds and the manner of obtaining the same.

Example I .-P1'eparat2'on of polyvinyl phthalimide 444 grams of N-vinyl phthalimide, obtained by pyrolysis of N-(beta-acetoxyethyl) phthalimide, were refluxed for a period of 48 hours in 2200 cc. of a solution consisting of 85 per cent ethylene chloride and 15 per cent methanol and containing 2.25 grams of benzoyl peroxide. The clear, viscous dope obtained was precipitated into ethanol, the polyvinylphthalimide being obtained in the form of a white, brittle, fibrous precipitate. The yield was 400 grams.

Example H.Polyvinylamine hydrochloride 100 grams of polyvinylphthalimide prepared as in Example I were ground to 20 mesh, mixed with 150 cc. of 85 per cent hydrazin hydrate and refluxed for one hour. A crystalline material separated out of solution on cooling. Without separating the crystals, water was added and the mixture heated until solution was complete. The solution was then cooled and precipitated into ethanol, yielding a white polymeric material which was filtered out and dried at 110 C. The yield of this product was 47 grams. The product was then mixed with an excess of concentrated hydrochloric acid, the mixture refluxed for two hours and filtered. The residue on the filter, containing both the polyvinylamine hydrochloride and phthalhydrazide, was mixed with water, stirred and centrifuged to remove the insoluble phthalhydrazide. The aqueous filtrate from the centrifuging operation was filtered and precipitated in ethanol to give a white polymer, which was purified by repeated extractions with metha-- I101. The yield of dried product was 18 grams.

Analysis for total nitrogen by the Dumas method.

showed 17.09 per cent by weight nitrogen compared with theoretical of.17.6 per cent by weightnitrogen calculated forpolyvinylamine hydrochloride, (C2H5N-HC1)1L. The total chlorine content was found to be 41.53 per cent by weight comparedwiththeoretical of 44.6 per cent by weight calculated for polyvinylamine hydrochloride. To determine the proportion of nitrogen present as amino nitrogen, the chlorine content; found was converted to equivalent nitrogen on: the basis that each mole of amino group had com-- bined with one mole of hydrogen chloride. This: gave a figure of 16.38 per cent by weight of nitrogen present as amino nitrogen, indicating thereby that the product obtained had approximately 95.8"'per cent of the nitrogen present in the form of free amino groups and 4.2 per cent present in the 'form of "incompletely hydrolyzedi imide group. The analytical findings indicated, therefore, that the product was substantially pure polyvinylamine hydrochloride. In: place of hydrochloric acid, there can be substituted in the above example, glacial acetic acid or alpha-chloropropionic acidto obtain polyvinylamine acetate or polyvinyl-alpha-chloropropionate.

Example III .Polyvinyl acetamide grams of polyvinylphthalimide were re-- fluxed in cc. of 85 per cent hydrazine hydrate. The imide dissolved completely and then a massof crystalline material separated out of solution. Water was added and heat applied until solution was again complete. A white, fibrous material was obtained by precipitating the solution in ethanol. The material was leached in fresh ethanol, and dried at'60" C. The yield was 69 grams. This intermediate addition polymer of indeterminate structure was ground to 40 mesh, added to cc. of acetic anhydride' and refluxed for 45 minutes. On cooling, a crystalline material began to separate out of the clear solution. The mixture was; poured into an excess ofacetone, whereby the crystalline material dissolved and a white resin was precipitated. Analysis of the resin gave by weight 15.62 per cent nitrogen, 8.12 per cent hydrogen, and 55.10 per cent carbon compared to theoretical of 16.5 per cent nitrogen, 8.24 per cent hydrogen and 56.5 per cent carbon calculated as polyvinyl acetamide, (C4H'1NOM.

In place of acetic anhydridein the above example, there can be substituted other acyl anhydrides, for example, propionic, butyric, phenoxyacetic and benzoic anhydrides to give corresponding acyl amides of polyvinylamine. Similarly, there can be substituted for polyvinylphthalimide in the above example, other polyvinyl cyclic imides, such as polyvinylsuccinimide, polyvinyl glutarimide, and their simpler substitution products.

Example I V.Polyoinylamine hydrochloride from polyvinyl acetamide 6 grams of polyvinyl acetamide were refluxed with 100 cc. of 6 normal hydrochloric acid for 3 hours. Upon cooling, a resin precipitated to the bottom of the flask. This resin was separated and dissolved in water and reprecipitated in ethanol to give a brittle, fibrous, straw colored material which was leached with fresh ethanol, redissolved in water, filtered and finall precipitated. in acetone. 'fhtssprodlmtt was identified as-polyvinylaminehydmchlcride.

Example VlPOlyvinylbcnzami-de 20. gramsof polyvinylamine hydrobromide were, To this solution,

was stirred for a. total of 3' hours- The precipitate was. separated fromthe solution, washed well.

with water and dried. It: was; then. dissolved. in methanol. and precipitated in water. After thorough dryingat 60: the dry resin. was: leached in dry acetone.

nitrogen by the Dumas method compared with. the. theoretical calculated value of; 9.5-2. percent for polyvinylbenzamide, (C9H9NO)7L-. The; polyvinylbenzamide was soluble in methanol, ethanol,

acetonewater mixture or dioxanewater mixture, and insoluble in. dry acetone, dry dioxane or water.

Example VI.-Polymnyldmine hydrobromide A. grams of polyvinylphthalimide. were added to a. mixture of 100cc. of water and 100: cc. of 85 per cent hydrazine hydrate, the reaction.

mixture refluxed for 18 hours and subjected. to-

steam, distillation, until a. total of about. 4 liters of distillate had been collected. The solution remaining in the. reaction vessel. was cooled, whereupon a. resinous mass settled out. of solution.

The supernatant. liquid. was. decanted, the resin dissolved in warm water, and then. precipitated.

in 48. per cent hydrobromic. acid. The solid ob.- tained separated and dispersed by in water. hydrazine. hydrobromide; dissolved leavingtphthale hydrazide as an insoluble material", which was: separated by centrifuging and filtering. The-filtrate. from this operation was then. concentrated; to a suitable viscosity, filtered and precipitated. in methanol, the. insoluble. polyvinylamine hydrobromide being precipitated, separated, extracted. with methanol and dried. Analysis gave 61.33 per cent by weight. of. bromine: and 10173 per cent. by weight of nitrogen. compared with therrtheorcth cally calculated values for polyvinylamine hydrobromide (CsHsNBrM of. 64.5 per cent bromine. and 11.23 per cent nitrogen, Assuming, that each bromine atom was combined. with one free. amino group, by calculation, the amount of bromine was equivalent to. 10.74 per cent nitrogen. In other words, all the. nitrogen in the compound. was present. as amino nitrogen, and the product was substantially pure. polyvinyl-amine hydrobromide.

B. 40 grams of polyvlnylphthalimide were refluxed with a mixture of 80 cc. of 85 per cent hydrazine hydrate and 80. cc. of distilled water; The resulting solution was. concentrated under reduced pressure on a steam bath.. After a pertion of the solvent. had been removed, a. mass of crystalline hydrazine. hydrate salt of phthalhydrazide, CaHsNzOa' (NI-I212, separated out of solution. The. reaction mixture was cooled and methanol added. The resin at this: stage was substantially polyvinylamine soluble; in methanol, whereas the hydrazine salt; of phthalhydrazid'e was insoluble in methanol. After filtering off the. latter, the filtrate was vacu-um distill-ed to. remove the methanol, and. the residue poured. into a solution or 30. grams, or hydroxide.

The resulting-sow A sample dried at 70 C4,. in vacuum contained 9.41 per cent by'weight:

The polyvinylamine.hydrobromideand Ba.(GI-Hz--8HzQ,- dissolved in. warm. water. Barium. phthalhydrazide crystallized. out of solution immediately. It was removed by filtration, the

filtrate cooled, and more of the barium phthalhydrazidethen filtered out. Carbon dioxide was passed into the filtrate to. remove excess barium salt as. insoluble barium carbonate. The precipitate. of barium salt. was. filtered. out, the filtrate concentrated under vacuum, and the additional bariumcarbonate which separated was filtered. oil. It was. found that a polyvinylamine salt of, carbonic acid had been formed which was.

stable in. boiling water. The filtrate containing the dispersion or dope or this carbonic acid salt. of. polyvinylamine was poured into concentrated hydrobromic acid. The precipitate of polyvinyl.- amine'hydrobromide was filtered out, washed well with fresh methanol, leached with additional methanol and dried. at 70 C. Analysis gave 61.12: per cent by Weight of bromine and 11.42.

per cent by weight of nitrogen. This calculates.

to. 9-3.8 per cent of the nitrogen present in the form. of aminov nitrogen.

Since both hydrazine. hydrobromide. and hydrazine hydrochloride are sufliciently soluble in methanol, ethanol or acetone, and the salts of polyvinyl are insoluble, these solvents can be used interchangeably in the precipitation, extraction and leaching steps of our process for the preparation of the salts of polyvinylamine.

Example VIL-Polym'nylamine hydrobmmide from po-Zyvinylacetamide 20 grams ofpolyvinyl' acetami'de were refluxed 1 with concentratedhydrobromic acid. The polyvinyl. acetamide dissolved, and then polyvinylamine hydrobromide settled out of solution. After cooling, the supernatant liquid was decanted, the resinous mass remaining then dissolved in water,

. the solution filtered and precipitated in methanol.

The precipitate of polyvinylhydrobromide obllained was extracted with fresh methanol and dried. Analysis gave 11.42 per cent by weight of nitrogen and 57.10 per cent by Weight of bromine.

Example VII;I.--Polycinylamine a'lpha-chloropropionate.

40 grams of polyvinylphthalimide were refluxed for one hour in a mixture of cc. of per cent hydrazine hydrate and 80 cc. of distilled Water. The resulting solution was concentrated under reduced pressure on a steam bath. After a portion of the solvent hadbeen removed, a mass of crystalline hydrazine hydrate salt of phthalhyd-razide separated out of solution. The reaction mixture was cool-ed and methanol added. The resin at thisstage was substantially polyvinylamine soluble in methanol, whereas the hydrazine salt of phthalhyclrazide was insoluble in methanol. After filtering oil the latter compound, the filtrate was vacuum distilled to remove the methanol, and the residue poured into a solution of 30 grams of barium hydroxide, dissolved in warm water. Barium phthalhydrazide crystallized out of soluti'on immediately. It was removed by filtration, the filtratecooled, and more of thebarium phthalhydrazide then filtered off. Carbon dioxide was passed into the filtrate to remove excess barium as the insoluble carbonate salt. The precipitate of barium carbonate was filtered off, the filtrate concentrated under vacuum, and the additional barium. carbonate which separated was filtered off. The resulting dispersion or dope containing the. carbonic acid salt of polyvinylamine was precipitated in methanol, and resin obtained, leached T5) and dried. The. dried resin was dissolved inan excess of alpha-chloropropionic acid. Carbon dioxide was evolved. The acid dope solution was precipitated in ethyl ether, the precipitate so obtained redissolved in methanol, reprecipitated in ethyl ether, and dried at 50 C. in Vacuum. Analysis of the resinous product gave 22.24 per cent chlorine by weight compared to 23.43 per cent by weight chlorine calculated for polyvinylamine alpha-chloropropionate (CH1ONO2CDn.

The following table represents a compilation of results found by analysis of various samples of our new hydrochloride and hydrobromide salts of polyvinylamine prepared in th manner of our examples. This table further illustrates the degree of hydrolysis of the cyclic imide groups to amino groups obtained by the process of our invention. Column I represents the per cent by weight of chlorine or bromine found, column II the per cent by weight of nitrogen found, column III the percent b weight of nitrogen calculated from the chlorine or bromine values of column I and is representative of nitrogen present as .amino nitrogen, and column IV represents the percentage of the total nitrogen found which is combined in the form of amino groups.

TabZe.AnaZ1/sis of polyvinylamine hydrochloride and hydrobromide Calculated theoretical for C2HtNC1-CI=44.G% by weight N =l7.6% by weight Calculated theoretical for GzHeNBl-BT=64.4% by weight N =11.3% by Weight Found by Analysis Calculated Per Cent Nitrogen Per Cent of Total if g from Halogen Nitrogen Com- Ogen T Analysis bined as -NH2.

41. 53 O1 17. 09 16. 38 95. 8 40. 80 C1 16. 53 16. 09 97. 2 56. 91 Br 10. 90 9, 97 91. 4 61. 33 Br 10. 73 10. 74 100. 0 60. 40 B1 11. 30 10. 58 93. 7 59. 64 Br 11. 38 10. 45 91. 9 60. 27 B1 11. 34 10.57 93. 2 62. 79 Br 11. 20 ll. 00 98. 2 61. 12 Br 11. 42 10. 71 93:. 8

In the above table, the results found by analysis are generally lower than the calculated theoretical values. This can be explained partly by the fact that the salts of polyvinylamine are quite hydroscopic.

Our new salts of polyvinylamine and N- acyl derivatives can be used as intermediates for the preparation of substantially pure polyvinylamine. The latter compound is extremely valuable for the further preparation of various amino substituted derivatives. Polyvinylamine or copolymers of polyvinylamine are excellent dispersing agents for silver halides and may be used as protective colloids in photographic emulsions either alone or in conjunction with vehicles such as polyvinyl alcohol, cellulose ethers, well hydrolyzed cellulosev esters, and similar kinds of materials.

What we claim is:

1. A process for preparing a salt of basic polyvinylamine in which at least 90% of the nitrogen atoms attached to carbon atoms in the polyvinyl chain are in the form of -NH2-I-IX groups, wherein X is an anion selected from the group consisting of a chloride ion, a bromide ion, an acetate ion, an alpha-chloropropionate ion and a bromobenzoate ion, comprising reacting a polyvinyl cyclic imide selected from the group consisting of polyvinylphthalimide, polyvinylsuccinimide and polyvinylglutarimide with hydrazine hydrate, treating the resinous product resulting therefrom with an, acid selected from the group 8 consisting of hydrochloric, hydrobromic, glacial acetic, alpha-chloropropionic and bromobenzoic acids, separatin and dispersing th mixture of insoluble salts obtained thereby in water, separating the filtrate from the dispersion, and precipitating it in a water-miscible monohydroxy aliphatic alcohol, and separating the precipitate of the salt of the basic polyvinylamine which forms. I

v 2. A process for preparing a salt of basic polyvinylamine in which at least of the nitro atoms attached to carbon atoms in the polyvinyl chain are in the form of NH2'HBr groups, comprising reacting polyvinylphthalimid with hydrazine hydrate, treating the resinous product resulting therefrom with hydrobromic acid, separating and dispersing the mixture of insoluble salts obtained thereby in water, separating the filtrate from the dispersion and precipitating it in a water-miscible, monohydroxy aliphatic alcohol, and separating the precipitate of polyvinylamine hydrobromide which forms.

. 3. A process for preparing a salt of basic polyvinylamine in-which at least 90% of the nitrogen atoms attached to carbon atoms in the polyvinyl chain are in the form of NIIz-HBr groups, comprising reactin polyvinylphthalimid with hydrazine hydrate, treating the resinous product resulting therefrom with hydrobromic acid, separating and dispersing the mixture of insoluble salts obtained thereby in water, separating the filtrate from the dispersion and precipitating it in methanol, and separating the precipitate of poly vinylamine hydrobromide which forms.

4. A process for preparing a salt of basic polyvinylamine in which at least 90% of the nitrogen atoms attached to carbon atoms in the polyvinyl chain are in the form of NH2-HCl group, comprising reacting polyvinylphthalimide with hydrazine hydrate, treating the resinous product resulting therefrom with hydrochloric acid, separating and dispersing the mixture of insoluble salts obtained thereby in water, separating the filtrate from the dispersion, and precipitating it in a water-miscible monohydroxy aliphatic alcohol, and separating the precipitate of polyvinylamine hydrochloride which forms.

5. A process for preparing a salt of basic polyvinylamine in which at least 90% of the nitrogen atoms attached to carbon atoms in the polyvinyl chain are in the form of -NHz-HC1 groups, comprising reacting polyvinylphthalimide with hydrazine hydrate, treating the resinous product resulting therefrom with hydrochloric acid, separating and dispersing the mixture of insoluble salts obtained thereby in water, separating the filtrate from the dispersion, and precipitating it in methanol, and separating the precipitate of polyvinylamine hydrochloride which forms.

6. A process for preparing a salt of basic polyvinylamine in which at least 90% of the nitrogen atoms attached to carbon atoms in the polyvinyl chain are in the form of -NH2-HOCOCI-I3 groups, comprising reacting polyvinylphthalimide with hydrazine hydrate, treating the resinous product resulting therefrom with glacial acetic acid, separating and dispersing the mixture of insoluble salts obtained thereby in water, separating the filtrate from the dispersion and precipitating it in a water-miscible monoliydroxy aliphatic alcohol, and separating the precipitate of polyvinylamine hydroacetate which forms.

7. A processfor preparing a salt of basic polyvinylamine in which at least 90% of the nitrogen atoms attached to carbon atoms in the polyvinyl 10 chain are in the form of -NH2-HOCOCH3 groups, REFERENCES CITED comprising reacting polyvinylphthalimide with hydrazine hydrate, treating the resinous product g figg ggi fg me of record m the resulting therefrom with glacial acetic acid, separating and dispersing the mixture of insoluble 5 UNITED STATES PATENTS salts obtained thereby in water, separating the Number Name Date filtrate from the dispersion and precipitating it in 233L905 Hanford et a1 Feb 18, 1941 methanol, and separating the precipitate of polyvinylamine hydroacetate which forms. OTHER R RE CES DELBERT REYNOLDS- 10 Jones et a1.: Journal of Organic Chemistry, WILLIAM KENYON- November 1944, pages 500-512. 

